This application is related to Japanese Patent Application No. 2002-5844 filed on Jan. 15, 2002, the contents of which are hereby incorporated by reference.
1. Field of the Invention
The present invention relates an air conditioner with an ejector cycle system having an ejector.
2. Description of Related Art
In a conventional ejector cycle system described in JP-A-5-149652, an ejector increases a pressure of refrigerant to be sucked into a compressor by converting an expansion energy to a pressure energy. Further, an evaporator is provided in the ejector cycle system so that air can be cooled by the evaporator. Recently, a dehumidifying and heating function for dehumidifying a compartment while preventing an excessive temperature decrease is required in an air conditioner. However, in the conventional system, there is not described regarding the dehumidifying and heating function.
In view of the foregoing problems, it is an object of the present invention to provide an air conditioner with an ejector cycle system, which has the dehumidifying and heating function.
According to the present invention, an air conditioner includes a compressor for sucking and compressing refrigerant, an exterior heat exchanger for performing heat-exchange between the refrigerant and air outside a compartment, a first interior heat exchanger for performing heat-exchange between the refrigerant and air to be blown into the compartment, a second interior heat exchanger for performing heat-exchange between the refrigerant and air to be blown into the compartment, an ejector, a gas-liquid separator for separating refrigerant into gas refrigerant and liquid refrigerant, and a switching unit for switching one of at least a cooling operation for cooling the compartment and a dehumidifying-heating operation for dehumidifying the compartment while restricting a temperature decrease in the compartment. The second interior heat exchanger is disposed at a downstream air side of the first interior heat exchanger. In the cooling operation, refrigerant in the first and second interior heat exchangers is evaporated, and refrigerant in the exterior heat exchanger is radiated. Therefore, the cooling capacity of the compartment can be improved. On the other hand, in the dehumidifying-heating operation, refrigerant is evaporated in the first interior heat exchanger while refrigerant in the second interior heat exchanger is radiated. Accordingly, in the air conditioner, the dehumidifying and heating function can be obtained. Thus, the compartment can be dehumidified while it can prevent temperature of the compartment from being excessively decreased.
Preferably, a decompression unit for decompressing refrigerant at least in the dehumidifying-heating operation is disposed in a refrigerant passage connecting the first interior heat exchanger and the second interior heat exchanger. Therefore, the dehumidifying operating of the compartment can be readily performed in the air conditioner using the decompression unit. Here, the first interior heat exchanger and the second interior heat exchanger can be arranged in series, relative to a refrigerant flow. In this case, in the cooling operation, refrigerant discharged from the compressor flows through the exterior heat exchanger, the nozzle of the ejector and the gas-liquid separator in this order, while liquid refrigerant in the gas-liquid separator flows through the first and second interior heat exchangers, the ejector and the gas-liquid separator in this order. On the other hand, in the dehumidifying-heating operation, refrigerant discharged from the compressor flows through the exterior heat exchanger, the second interior heat exchanger, the decompression unit, the first interior heat exchanger and the gas-liquid separator in this order while bypassing the ejector.
On the other hand, the first interior heat exchanger and the second interior heat exchanger can be arranged in parallel relative to a refrigerant flow, at least in the cooling operation. In this case, at least in the dehumidifying-heating operation, a part of high-pressure refrigerant discharged from the compressor, before being decompressed, is introduced into the second interior heat exchanger, and flows into the first interior heat exchanger after being decompressed in the decompression unit, while the other part of the high-pressure refrigerant is introduced into the nozzle of the ejector. In this case, the dehumidifying and heating function of the compartment can be obtained while power consumed in the compressor can be reduced.
Further, the switching unit can be disposed to switch one of the cooling operation, the dehumidifying-heating operation, and a heating operation for heating the compartment. In this case, in the heating operation, refrigerant is evaporated in the exterior heat exchanger while refrigerant is radiated in both the first and second interior heat exchangers. Specifically, in the heating operation, refrigerant discharged from the compressor flows through the first and second interior heat exchangers, the nozzle of the ejector and the gas-liquid separator, while liquid refrigerant in the gas-liquid separator flows through the exterior heat exchanger, the ejector and the gas-liquid separator in this order. Accordingly, the cooling operation, the dehumidifying-heating operation and the heating operation can be selectively switched in the air conditioner.